It is said that Joshinsai planned an eight mat room suitable for the shichijishiki (seven chanoyu group training exercises). Sottakusai built a new seven mat room as a practice room after the Great Fire of Tenmei, on the west side of Zangetsutei's tsuginoma, or 'next room'. This tea room was apparently devised so that it would not be suitable for the shichijishiki.
The Shichijo tea room faces the roji (tea garden) on the west side of Zangetsutei and at the eastern end is a nure-en (veranda exposed to the rain). At the end of the veranda there is a wash basin. Entering the room from the veranda, there is first an irikawa (passageway between the veranda and the tatami room).
The room has six mats and the toko (alcove) is on the east side in the centre. Next to the toko there is a daime (small-sized mat). To describe the room accurately, it is a rokujo-daime (six mats and one daime mat). The mat at the back of the room is the host's mat. The depth of the alcove is less than the width of a tatami, so there is a board across the front of the toko and the host's mat.
The sadoguchi (host's entrance) has two fusuma (sliding paper-covered doors) and the fact that it is a little lower than the other entrances attracts attention. To have the host's entrance a little low is becoming for a tea room. The toko is in the middle of the room, so there are tokobashira (alcove pillars) on both sides. The one on the right is a red pine log with bark still on. In the opening in the lower part of the wall between the toko and the tatami next to it, there are lengths of bamboo which differ in height, which gives a feeling of lightness.
The structure of the present Shichijo is almost exactly the same as the one in Sottakusai's time.